Make sure NdotV does not reach 0

Assets/ScriptableRenderLoop/ShaderLibrary/Common.hlsl

 float GetShiftedNdotV(inout float3 N, float3 V, bool twoSided)
 {
     float NdotV = dot(N, V);
-
-    if (!twoSided && NdotV < 0.0)
+    float limit = 1e-6;
+    
+    if (!twoSided && NdotV < limit)
-        const float magic = 1e-5f;
-        // We do not renormalize the normal because { abs(length(N) - 1.0) < magic }.
-        N    += (-NdotV + magic) * V;
-        NdotV = magic;
+        // We do not renormalize the normal because { abs(length(N) - 1.0) < limit }.
+        N    += (-NdotV + limit) * V;
+        NdotV = limit;
     }
 
     return NdotV;